1. Technical Field
The present invention relates to liquid jet heads, line type liquid jet heads, printers, line type printers and film forming apparatuses.
2. Related Art
Liquid jet heads may be used, in addition to ordinary printing, in film forming apparatuses used in the steps of forming patterns in semiconductor devices, and forming color filters in manufacturing liquid crystal displays, plasma displays, organic EL displays and electrophoretic displays, and in the steps of forming patterns of light emission layers and the like on substrates. Such apparatuses are equipped with a mechanism that controls the nozzles to eject liquid at target positions while changing relative positions between a medium and the liquid jet head. One of the performances required for a liquid jet head is the accuracy in coating position of liquid when the liquid is coated on a medium. In order to coat liquid on a medium with high positional accuracy, accurate operation mechanisms and high assembly accuracy are required. The larger a pattern area to be formed, the more severe the requirement becomes. The apparatus described above is generally equipped with a liquid jet head having a plurality of rows of regularly arranged nozzles for high-speed printing.
A liquid jet head in related art may have a structure that includes a plurality of nozzle rows each having a plurality of regularly arranged nozzles, wherein the nozzle rows may eject, for example, inks in different colors, respectively. However, the plurality of nozzle rows in related art are arranged in a plane, and therefore the nozzle rows need to be arranged at relatively large intervals because the ink flow passages and the driving mechanism for ink ejection are relatively large in size. Therefore, when inks in multiple colors need to be coated at specified target positions on a medium, the medium or the nozzles need to be accurately moved in a relatively long distance to the target positions, which requires the apparatus to have extremely high mechanical precision. Also, inks ejected from specified ones of the nozzles and coated at target positions on a medium may cause deformation in the medium before the other ones of the nozzles reach the target positions, and errors caused by such deformation need to be considered.
To address the problems described above, there has been proposed a method of feedback controlling the positional shift and liquid ejection in order to improve the accuracy in coating positions. Japanese Laid-open Patent Application JP-A-2007-144867 is an example of related art. However, according to this method, it is expected that the faster the coating operation, the more difficult the control becomes.